Cod sursa(job #2068625)

Utilizator avramraresAvram Rares Stefan avramrares Data 18 noiembrie 2017 10:02:21
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.04 kb
#include <fstream>

using namespace std;
ifstream f("evaluare.in");
ofstream g("evaluare.out");
char s[100004],*p;
int sol;
int eval();
int termen();
int factor();
int main()
{
    f.getline(s,100004);
    p=s;
    g<<eval();
    return 0;
}
int eval()
{
    int r;
    r=termen();
    while(*p=='+' || *p=='-')
    {
        if(*p=='+')
        {
            ++p;
            r+=termen();
        }
        else
        {
            ++p;
            r-=termen();
        }
    }
    return r;
}
int termen()
{
    int r;
    r=factor();
    while(*p=='*' || *p=='/')
    {
        if(*p=='*')
        {
            ++p;
            r*=factor();
        }
        else
        {
            ++p;
            r/=factor();
        }
    }
    return r;
}
int factor()
{
    int r=0;
    if(*p=='(')
    {
        ++p;
        r=eval();
        ++p;
    }
    else
    {
        while(*p>='0' && *p<='9')
        {
            r=r*10+(int)*p-'0';
            ++p;
        }
    }
    return r;
}